I’m building a workbench (like this one: http://lumberjocks.com/kem/blog/5155) out of white oak 2×3’s. Laminated top, legs will be 4 2×3’s glued together to make a 3×5 leg, and 2 boards edge glued for stretchers. I got the wood from a local mill that had them setting in an open barn/shed (so they were outside but dry and covered). When I got home I was getting about 15-18% moisture readings from all boards. In a couple days they all dropped to about 14-15% and have all sat about 14% for the past 5 days or so. I’m anxious to get started on the legs, but I’m not sure what to expect as far as how low it should go. I’ve got a cedar 2×4 from home depot thats been in the garage a few months that measures 9%. Humidity in the garage is 50-60% this time of year (attached to house, unheated).

Can I start planing/flattening/glueing the leg pieces together now or should I give it some more time? What should I expect the moisture to be in the wood when it is ready to be worked? Any other advice?

9 replies so far

Not likely to go much below 14% unless you bring the wood into a climate controlled environment. Given that the shrinkage on your bench legs will be very small since they are only 5” wide on the widest dimension, I would go ahead and make them up. I have done it before without any problems. If it was a 48” table top glue-up, then that would be another story.

50-60% air moisture content should get wood to around 8-10%, so that wood is right on. I agree with Rick, rough it out then let it set and keep an eye on it. The moisture on the inside needs time to get out and is difficult to read with a moisture meter (unless yours uses pins that go in that far); it is that moisture that causes problems. I’d recommend a week; if it is still the same, have at it.

Sorry I disagree with” the going for it “scenario even if wood is still wet. Using wood for projects before it’s dry is asking for trouble because the wood has a greater possibility of twisting and cupping when it’s not dry and then does dry out after the projects built. Precutting your wood oversize and letting it accumulate before using it is always a great Idea even for wood that is dry. If your having 50-60% humidity in your shop you might consider getting a dehumidifier to bring that percentage down.There are a number of dehumidifiers that are relativity low in cost and can help a lot.

The cedar from HD was kiln dried. I think 8% for unassisted air drying is hopeful but not realistic at those humidity levels. Take a piece of wood and beginning at the corners, cut a deep V notch in one end. If the notch closes up the wood is not at equilibrium.

I agree with Jim about waiting to get the % down. Ricks got a good idea about the notch…learned something today. I have a shop that’s not climate controlled and have plenty of wood that has air dried to the 10% range, give or take a bit.

The smile will try to straighten. On legs I do (), haven’t had one fail yet.

On the stretchers I will give you my experience making tabletops. Some claim the boards should be alternated so that any cup cancels but that isn’t really how it works, worst case scenario you end up with a washboard. If you turn the growth rings the same direction, the theory is it magnifies any cupping. I’ve made tabletops both ways with the same result – no cupping at all. With one exception – the first table I made wasn’t finished equally on both sides, years later it was placed above heat vent, the bottom dried out and it cupped upward. (Might have happened regardless of finishing). But it was easy to fix, remove the top, kerf the bottom, refinished and reinstall. A washboard top must be planed flat. All that said, your stretchers will be in tension across the width and shouldn’t be able to cup without twisting the legs which is unlikely. So I say it doesn’t matter.

I have no strong opinion on the top. Quartersawn would be best but if that isn’t an option then I’d just pick some alternating pattern and go with it.